mc145193 Datasheet, PDF (15/24 Pages) Motorola, Inc – 1.1 GHZ PLL FREQUENCY SYNTHESIZER

MC145193
Figure 16. R Register Access and Format
(16 Clock Cycles are Used)
ENB
Note Note
CLK
1
23
45
6
7
8
9
10 11 12 13 14 15 16 ₄
5
MSB
LSB
Din
R15 R14 R13 R12 R11 R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 R0
0 Crystal Mode, Shut Down
1 Crystal Mode, Active
2 Reference Mode, REFin Enabled and REFout
Static Low
3 Reference Mode, REFout = REFin (Buffered)
4 Reference Mode, REFout = REFin/2
5 Reference Mode, REFout = REFin/4
6 Reference Mode, REFout = REFin/8 (Note 3)
7 Reference Mode, REFout = REFin/16
Octal Value
0 0 0 0 Not Allowed
0 0 0 1 R COUNTER = ÷ 1 (Note 6)
0 0 0 2 Not Allowed
0 0 0 3 Not Allowed
0 0 0 4 Not Allowed
0 0 0 5 R COUNTER = ÷ 5
0 0 0 6 R COUNTER = ÷ 6
0 0 0 7 R COUNTER = ÷ 7
0 0 0 8 R COUNTER = ÷ 8
· · ··
· · ··
· · ··
1 F F E R COUNTER = ÷ 8190
1 F F F R COUNTER = ÷ 8191
Binary Value
Hexadecimal Value
NOTES:
1 Bits R15 through R13 control the configurable “OSC or 4–stage divider” block (see Block Diagram).
2 Bits R12 through R0 control the “13–stage R counter” block (see Block Diagram).
3 A power–on initialize circuit forces a default REFin to REFout ratio of eight.
4 At this point, bits R13, R14, and R15 are stored and sent to the “OSC or 4–Stage Divider” block in the Block Diagram. Bits R0 – R12
are loaded into the first buffer in the double–buffered section of the R register. Therefore, the R counter divide ratio is not altered yet
and retains the previous ratio loaded. The C and A registers are not affected.
5 Optional load pulse. At this point, bits R0 – R12 are transferred to the second buffer of the R register. The R counter begins dividing
by the new ratio after completing the rest of the present count cycle. CLK must be low during the ENB pulse, as shown. The C and A
registers are not affected. The first buffer of the R register is not affected. Also, see Note 3 of Figure 15 for an alternate method of loading
the second buffer in the R register.
6 Allows direct access to reference input of phase/frequency detectors.
MOTOROLA WIRELESS SEMICONDUCTOR
15
SOLUTIONS – RF AND IF DEVICE DATA